Digital camera manufactures have done a good job of translating the digital process into terms we are familiar with in our film photography. Exposure and focus settings are similar. The camera shape and look are similar.
However new words are introduced and some terms are different, and most camera manuals will explain some of the more common. Only a few will be covered here. You are encouraged to check out your local public library for more information, as the more you know, the more you will be able to apply in your own photographs.
Don't be put off by the title of this lesson; I do not intend to delve very far into the technical areas, only as far as necessary to explain later lessons.
Light from the object is reflected through the lens onto either a strip of film---or a CCD (Charge-Coupled Device). The CCD 'screen' is a group of photocells, each of which converts a very small portion of the image into an electrical impulse which is then written to the media card. These little portions of the image data are called pixels (short for picture elements) and have everything to do with our digital photographs! The total number of pixels the CCD screen contains is what determines a camera's 'rating' of megapixels, 2.1 or 3.0 megapixel for example---and is a way of measuring how many million pixels the camera's highest quality setting will capture.
Each pixel is assigned only one color. In other words, each photocell interprets the tiny bit of light it receives. Let's say the light is reflected from an African violet leaf. A photocell receives light and must determine what color and value it will record, and it can only record one. On a single violet leaf, there will be a basic leaf color, such as light green or olive green. There will also be nearly white highlights and nearly black shadows... as well as a multitude of shades in between. Each vein and hair will present a constantly changing order of colors and values.
Therefore, the larger the number of photocells that are recording these pixels (picture elements), the more detail, colors, values, etc. that will be contained in the image file on the media card. This is called the 'resolution' of an image.
Those many, many pixels are saved as a single image file, and in one of several file types. The most common is JPG.
Just as there are adjustments to the light as it enters the camera, so there are adjustments to the way that the camera 'saves' the image. They all describe the amount of compression of the image... from extremely small (compressed) gif files to uncompressed TIFF files.
The adjustments to the camera, as well as the adjustments to the image, will be briefly covered in later lessons.
All you really have to remember is the basic rule: the fewer the pixels recorded and the more the image is compressed to make a small file the fewer the details. The more pixels recorded and the less the image is compressed will leave more details in the final photo.
(My personal opinion is: the digital revolution should forever erase all fear of taking too many photos AND the hard-to-break habit of 'saving film', or in this case, camera cards! Within a minute, you may preview the image on the display screen... saving if it is just what you wanted... or deleting if it is not. You can take a whole card full of nicely detailed, large photos---and in fifteen moments transfer the images to your computer or a CD and, ab-ra-ca-da-bra, the card is empty again! It is the same as using a 110 camera to take the family portrait, when you could use a professional photographer's studio camera! )
A few words on the physical characteristics of digital cameras: There are two ways of 'looking through the camera": through a viewfinder, essentially a hole cut in an upper corner of the camera, or TTL (through the lens). Many cameras also allow you to see what the camera sees on the display screen, even while taking the photo. Don't forget that if your camera uses a viewfinder, what YOU see is not the image recorded. (My personal opinion again: I bought my camera not for it's megapixel---it is not large, but for it's 'real camera' features such as TTL viewing and the zoom lens. If your camera does not have TTL viewing, please use the display screen option... even though it does consume more battery power!)
Digital cameras have many buttons and dials... and all have wonderful possibilities. While photos taken on the Auto mode are very good.... often as good as any: at least take a moment to read the owner's manual about the other settings. The Auto mode was set to function on an average photo.. which includes people taken from a distance of some feet, or outdoor sunlit shots. Our African violet photos are far average! (Personally, I use a Program mode, which lets me set a few starting points, but using the camera's automatic focus, etc. I set other options as I take the photos---adjusting according to how dark, light, sharp or blurry the images look.)
Don't be intimidated---just being introduced to the terms will be helpful. Understanding how your camera works will make you a better photographer, or maybe I should say: more versatile. As with most things in Life, "Knowledge is power". Power up!
This is the only 'dry' lesson, I promise! On to the fun......!
I have not yet found the 'perfect' online photography course, although these are interesting:
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